(a) Field of the Invention
The present invention relates to a method of forming carbon nanotubes, a field emission display device having the carbon nanotubes formed through the use of the method, and a method of manufacturing the field emission display device, and more particularly, to a method of forming carbon nanotubes of which a generation density can be controlled, a field emission display device having the carbon nanotubes formed through the use of the method, and a method of manufacturing the field emission display device.
(b) Description of the Related Art
Carbon nanotubes (CNT) are carbon allotropes and have a tube shape in which carbon atoms are coupled to each other in a hexagonal honeycomb shape. Since such carbon nanotubes have excellent mechanical characteristics, electrical selectivity, and field emission characteristics, the carbon nanotubes are widely used in various fields of electrics and electronics.
Particularly, studies for applying the carbon nanotubes to a field emission display device (FED) which is one of next-generation flat panel display devices have been vigorously carried out.
The field emission display device (FED) serves as a display device, wherein when a positive voltage of several hundreds volts is applied to a cone-shaped electron emission portion from an external gate electrode, electrons are emitted from the electron emission portion under a strong electric field and the emitted electrons collide with an anode electrode coated with fluorescent substances.
In such a field emission display device, a silicon tip or a metal tip made of molybdenum (Mo) or the like was mainly used as the electron emission portion. However, such a field emission display has problems in that an operation voltage is very high and leakage current is high due to deterioration of the tip resulting from emission of a high current, thereby deteriorating reliability and performance of the device.
A field emission display device using carbon nanotubes as the electron emission portions has been suggested for solving such problems.
However, since it is difficult to effectively control a generation density of the carbon nanotubes, the field emission display device has problems in that a production yield is low and a large size cannot be realized.